scholarly journals Behavior of triangular shell-element stiffness matrices associated with polyhedral deflection distributions.

AIAA Journal ◽  
1968 ◽  
Vol 6 (2) ◽  
pp. 374-376 ◽  
Author(s):  
SENOL UTKU ◽  
ROBERT J. MELOSH
Keyword(s):  
Shell Element ◽  
Triangular Shell Element ◽  
Stiffness Matrices

Triangular Shell Element for Large Rotations Analysis

AIAA Journal ◽  
2003 ◽  
Vol 41 (12) ◽  
pp. 2505-2508 ◽  
Author(s):  
R. Levy ◽  
E. Gal
Keyword(s):  
Shell Element ◽  
Triangular Shell Element ◽  
Large Rotations

scholarly journals Local Elastic and Geometric Stiffness Matrices for the Shell Element Applied in cFEM

2017 ◽  
Author(s):  
Dávid Visy ◽  
Sándor Ádány
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Shell Element ◽  
Numerical Examples ◽  
Geometric Stiffness ◽  
Stiffness Matrices ◽  
Plane Element ◽  
Unusual Combination ◽  
Shell Finite Element ◽  
Lagrange Strain

In this paper local elastic and geometric stiffness matrices of ashell finite element are presented and discussed. The shell finiteelement is a rectangular plane element, specifically designedfor the so-called constrained finite element method. One of themost notable features of the proposed shell finite element isthat two perpendicular (in-plane) directions are distinguished,which is resulted in an unusual combination of otherwise classicshape functions. An important speciality of the derived stiffnessmatrices is that various options are considered, whichallows the user to decide how to consider the through-thicknessstress-strain distributions, as well as which second-order strainterms to consider from the Green-Lagrange strain matrix. Thederivations of the stiffness matrices are briefly summarizedthen numerical examples are provided. The numerical examplesillustrate the effect of the various options, as well as theyare used to prove the correctness of the proposed shell elementand of the completed derivations.

Control Effectiveness of Segmented Actuators Laminated on Ring-Shells

1997 ◽  
Author(s):  
R. Ye ◽  
H. Bahrami ◽  
H. S. Tzou
Keyword(s):  
Finite Element ◽  
Distributed Control ◽  
Piezoelectric Actuators ◽  
Shell Element ◽  
Circular Ring ◽  
Control Effectiveness ◽  
Triangular Shell Element ◽  
Circular Ring Shell ◽  
System Equations ◽  
Ring Shell

Abstract Distributed control effectiveness of ring-shells laminated with segmented actuators is investigated in this paper. A new laminated quadratic piezoelastic triangular shell FE is developed using the layerwise constant shear angle theory. Element and system equations are also derived. The developed piezoelastic triangular shell element is used to model a semi-circular ring shell with various segments of distributed piezoelectric actuators. Finite element (triangular shell FE) solutions are compared with the theoretical, experimental, and finite element first. Natural frequencies and distributed control effects of the ring shell with different length of piezoelectric actuators are also studied. Control effectiveness is evaluated and optimal length of the actuator is recommended.

The modal behavior of the MITC3+ triangular shell element

2015 ◽  
Vol 153 ◽  
pp. 148-164 ◽  
Author(s):  
Youngyu Lee ◽  
Hyeong-Min Jeon ◽  
Phill-Seung Lee ◽  
Klaus-Jürgen Bathe
Keyword(s):  
Shell Element ◽  
Triangular Shell Element ◽  
Modal Behavior

Elastic Analysis of a Skull

1973 ◽  
Vol 40 (4) ◽  
pp. 838-842 ◽  
Author(s):  
C. H. Hardy ◽  
P. V. Marcal
Keyword(s):  
Finite Element ◽  
Composite Material ◽  
Elastic Stress ◽  
Shell Element ◽  
Elastic Analysis ◽  
Triangular Shell Element ◽  
Skull Measurements ◽  
Doubly Curved

A finite-element elastic analysis is made of a skull. Measurements were made of the geometry and thickness of a skull. The skull was then idealized with a doubly curved and arbitrary triangular shell element. Results suggest that the skull is well built for resistance to front loads. The importance of using a composite material through the thickness of the shell was established. On the basis of tensile cracking at maximum elastic stress, loads of 3500 lb and 1400 lb were predicted for the first cracking of the skull due to front and side loading, respectively.

Resolution of Defects in Degenerated Shell Elements Through Modification of Gauss Integration

2003 ◽  
Vol 17 (08n09) ◽  
pp. 1877-1883 ◽  
Author(s):  
Y. D. Kwon ◽  
N. S. Goo ◽  
B. S. Lim
Keyword(s):  
Integration Method ◽  
Time Integration ◽  
Shell Element ◽  
Zero Energy ◽  
Integration Rule ◽  
Shell Elements ◽  
Reduced Integration ◽  
Stiffness Matrices ◽  
Assumed Strain ◽  
Degenerated Shell Element

In this paper, the modified Gauss integration method is developed to eliminate the shear and membrane locking phenomena of the degenerated shell element. The behavior of the element based on the Mindlin/Reissner theory in plates and shells sometimes causes a problem. In displacement-based shell elements, the full integration of stiffness matrices leads to a 'locking' or over-stiff behavior. The selective or reduced integration procedures may often overcome these difficulties, while overstiff solutions may still occur in the analysis with a highly constrained boundary. Except for the six zero-energy modes associated with shell rigid body movements, during the reduced integration of the stiffness matrices, many extra zero spurious energy modes are introduced due to reduced integration. This is a serious defect of degenerated shell element. In previous studies, several methods such as the addition of nonconforming displacement modes, an assumed strain method, and hybrid and mixed elements have been introduced in an attempt to overcome these difficulties. In this study a newly modified Gauss integration method combining both a selective and a weight-modified integration is suggested. Numerical experiments show that the new selective integration and weight-modified integration rule is very effective in eliminating the shear and membrane locking in static and modal analyses, and removes spurious zero-energy modes as well. Also, the effectiveness of proposed shell element is tested by applying it to some example problems. We solved post-buckling problem by the Riks arc-length method and dynamic problem by the Newmark's time integration method, as well as static problems.

Sign in / Sign up

Export Citation Format

Share Document